If I remember correctly(and i'm getting kind of old) Cope wants 15 springs in the clutch pack, 2 servo springs and a 4.2 lever. All three of these along with clutch pack clearance and band adjustment affect the timing of releasing 2nd gear and applying 3rd. The loaded drum and servo spring that you bought from other sources may be a mismatch with your vb. Not all valve bodies work the same. You may need to change or add springs to get the overlap correct. You really should call Cope and ask.
This is the right answer. When I was running 3 speeds, we would tune the springs to get the right shift at 7000RPM WOT. The type of band construction also has an effect. It's trial and error. More spring pressure = slower apply & faster release. When it's right, it will have noticeable overlap at low RPM on the stands.
